A.J. Green
It's hard to ask for more minutes for A.J. Green when he's not having his best series.
He hasn't hit a three yet (he's 0-of-3), and it is almost mandatory for him to start doing so if he wants to earn a bigger role, but in the meantime, he's actually doing more than that. His defense is way better than Beasley's, and he's proving to be better at decision-making, too.
Currently, only a red-hot shooting night by Beasley would justify playing him over Green. And sadly, he hasn't had many of those in a long time.
At this point, none of them are shooting well enough to not even think about playing the other one, but Green might deserve to be the first option on this spot. In Game 2, he already had more minutes than Beasley, proving Rivers was more patient with him after a few misses than he was in Game 1, so he might be the first of both to get into the court in Game 3. Honestly, he probably should.
Beasley started the season as an amazing shooter but has noticeably fallen off in the last months, and opponents have realized. He shot 3-of-7 in Game 1, which is good, but he hasn't been treated as a real threat by the defense; he just doesn't generate that much space and isn't punishing defenders who don't pay him that much attention. And he's a pretty one-dimensional player, meaning that if he's not hitting threes, he's basically not bringing anything.
Beasley shouldn't be erased from the rotation. The Bucks don't have that much offensive power to just sit a potentially great shooter. But at this point, there's not much of a case for him to be the first bench player to jump on the field. Both Green and he need a chance to shoot a few threes every game because if they make them, the Pacers will be forced to adjust their defense on the fly, and the game could swing. Since A.J. can be impactful in more areas, he feels less of a coin flip and can allow himself a few misses without being a total liability on everything else.
That said, these are just some ideas that could work, as much as they could be proven wrong. Doc Rivers is probably thinking about his own adjustments, and it will be interesting to see which they are and how they can impact the upcoming pivotal Game 3.